1.Piccadilly Circus. (Opening credits and in The Great Game).

BBC

BBC

At the start of every episode viewers see a glimpse of Piccadilly Circus, as well as a shot of Big Ben, the London Eye and the Thames in a London montage. It also appears more in The Great Game episode later in series one. Piccadilly Circus is famous for its lit up advertisements and is popular with tourists.

2.Russell Square Gardens, Camden.

John Watson bumps into his old friend Mike Stanford in Russell Square Gardens near the beginning of the first episode, and it proves a fateful meeting as it leads him to meeting Sherlock Holmes for the first time. The gardens are only 10 minutes walk from the real Speedy's Cafe and the street Sherlock's flat is in - although on screen they're supposed to be in Baker Street. The chance encounter is shortly followed by Watson meeting Sherlock and them then moving in together.

3.Speedy's Cafe. (North Gower Street, Camden).

Speedy's Cafe is frequently shown in each episode of the show due to it being placed next to Sherlock and Watson's flat. It may be billed as being on Baker Street, but it is in fact on North Gower Street in Camden. And you can go and enjoy some food and drink there yourself, on their Twitter page they describe themselves as having "fresh food at excellent prices". The interior is even still painted the same as it appeared in Series Two of the show.

Sherlock and Watson live at 221B Baker Street, but it's actually 187 North Gower Street in Camden, next door to Speedy's Cafe. During filming producers would remove the real door and put the 221B facade with the recognisable door knocker in its place. But it is now a permanent fixture following the success of the series. The interior, however, was shot at a production facility in Cardiff, Wales, up until series three, when it closed in 2011.

In A Study In Pink Sherlock and Watson head for a bite to eat while trying to solve the identity of a mass murderer, who turns out to be a taxi driver who had parked up outside. They sit down in Tapas Brindisa Soho restaurant, said in the show to be in Northumberland Street in Westminster, but it's actually located at 46 Broadwick Street in Soho. You can visit the tapas restaurant yourself but reservations are required.

6.Northumberland Street. (Broadwick Street).

Again on screen Sherlock is said to be in Northumberland Street, but the scene when he runs out to the taxi is in Soho. In the real Northumberland Street you will find a pub called The Sherlock Holmes, as well as a road named the Great Scotland Yard in ode to the famous storylines.

7.Taxi chase through Soho.

In A Study In Pink Sherlock calculates how he can out run the black cab holding who he believes to be the suspected murderer. The map he imagines in his head takes in Poland Street, Berwick Street, D'Arblay Street and Wardour Street. The plan doesn't quite add up in reality. When they finally cross paths with the taxi it is actually filmed in Cardiff. But you can easily roam around the streets of Soho mentioned in the map, closest tubes Tottenham Court Road and Oxford Circus.

8.Roland Kerr College. (School of Chemistry, Cardiff University).

The finale of A Study In Pink sees Sherlock taken to a building by the taxi driver, where they endure a face off and Sherlock almost dices with his own death - until Watson of course saves him. The college is a made up venue in London and the exterior is actually a part of Cardiff University, with the help of some extra special graphics to add to the effect.

9.Tower 42, Old Broad Street.

In The Blind Banker Sherlock and Watson visit financial office Shad Shanderson to solve another mystery. The company is actually fictitious but the real Tower 42 does in fact include office blocks, as well as restaurants and bars - including Rhodes 24 and Vertigo 42, with stunning views of the London skyline. It was at one point the tallest building in the UK, but it has since been taken over quite a few times, most recently by The Shard in the capital.

10.The Gherkin.

Sherlock steps outside the office in Tower 42 to get some clues, and in the process shows us some of the surrounding London view. The tall pointy building is known as The Gherkin, real name 30 St Mary Axe. The skyscraper stretches across 41 floors and is one of the city's most recognisable landmarks.

While a lot of the China Town scenes were filmed in the real London district, the Lucky Cat Shop was actually shot in Wales. It was transformed especially for the episode and now houses a shop called Glamour And Glitz. They also hung lanterns across the street to emulate Gerrard Street in London.

14.Trafalgar Square, London.

The historic landmark is a well known area of the British capital and has been shown twice in Sherlock so far. It includes Nelson's Column, numerous commemorative statues and a fountain in the centre.

15.National Antiques Museum. (National Museum Cardiff).

BBC

BBC

In the series Sherlock and Watson appear to enter the museum from Trafalgar Square, but it was again filmed in Cardiff. As well as appearing in The Blind Banker episode, it has also previously been seen in Doctor Who.

16.Hungerford Bridge, Victoria Embankment.

Sherlock enlists the help of a graffiti artist and the trio cross Hungerford Bridge in Victoria Embankment, which crosses over the Thames. Nearby landmarks include the London Eye and Big Ben. It also leads to the Southbank Skate Park.

17.South Bank Skate Park.

Sherlock discovers yet more clues when he searches the graffiti plastered across the South Bank Skate Park, where onlookers will often see skateboarders and BMX bikers. London Mayor Boris Johnson has recently called for the skate park to stay despite efforts for redevelopment in the area.

18.Chinese Theatre. (Newbridge Memorial Hall, Wales).

The episode culminates at a Chinese Theatre. But rather than being based in London, it's actually filmed in the Newbridge Memorial Hall in Newbridge. And thanks to its inclusion in Sherlock it has since received a lot more funding to help restore it.

20.OXO Tower Foreshore.

A body is found washed up from the Thames in front of the OXO Tower in the show. In real life it is open to public access, but can sometimes be tricky to get down to depending on the tides. St Paul's Cathedral is nearby.

21.Victoria Embankment.

BBC

Sherlock and Watson jump over barriers at Victoria Embankment, right by Waterloo Bridge. You can easily walk up the whole stretch of Victoria Embankment along the Thames, running from Westminster Bridge to Blackfriars Bridge.

22.Waterloo Bridge.

Sherlock and Watson jumped the railings to access the 'homeless network' under Waterloo Bridge. The bridge stretches across the Thames from The Strand to the South Bank, where you can find the large circular IMAX cinema in Waterloo.

23.Bristol South Swimming Pool.

The scene in which viewers see Moriarty, Sherlock and Watson in the same room together at the end of the first series. Watson is strapped to a bomb, while Sherlock's life is also put in danger, but it's left on a cliffhanger, before the swimming pool is again seen at the start of the second series. The pool is the same one where Mark Gatiss, who plays Sherlock's brother Mycroft, actually learnt to swim as a child.

24.Irene Adler's House, Eaton Square, London.

The second series kicks off with the introduction of Irene Adler in A Scandal In Belgravia. Her house is located at 44 Eaton Square in the up market Belgravia area. Again the residence has previously been used to shoot Doctor Who, hardly surprising as Steven Moffat has had a hand in both shows.

25.Buckingham Palace. (Goldsmiths' Hall).

Sherlock is summoned to Buckingham Palace, but insists on coming in just his bed sheet. Exteriors of the real Buckingham Palace are used but The Queen was left undisturbed as the inside shots were actually filmed in Goldsmiths' Hall's Drawing Room.

26.Boscobel Place, Belgravia.

Sherlock and Watson end up in a punch up before trying to get into Irene Adler's house. In the scene Sherlock states that the quiet residential road is two streets away from Adler's home, but it is in fact just one street away as shown on the map (L).

27.Battersea Power Station.

Another big landmark in the capital, close to Vauxhall tube. Adler reveals she's still alive when she invites Watson to meet her at the iconic building. A lot of the interiors are also used throughout the episode.

28.Millennium Bridge.

A lot of the South Bank is covered in A Scandal In Belgravia, including yet another bridge. The Millennium Bridge opened in 2000 and stretches from outside St Paul's Cathedral. Irene Adler stands on the bridge when she finally gets a text message from Holmes.

30.Hound Tor, Dartmoor, Devon.

Hound Of The Baskerville takes the men to Dartmoor to investigate their latest mystery. Sherlock is seen climbing on a large rock formation called Hound Tor, which is said to be the inspiration for Sir Arthur Conan Doyle's The Hound Of The Baskervilles.

31.The Cross Keys Pub, Dartmoor. (The Bush Inn, Wales).

Throughout the episode Sherlock and Watson are seen in The Cross Keys Pub, purported to be in Dartmoor's fictional village Grimpon. But it's actually a pub called The Bush Inn in Wales and scenes were filmed inside and outside of the venue.

The Baskerville Research Facility is seen throughout Hound Of The Baskerville but was actually shot at the Dynevor Arms LNG Storage Facility in Wales. It is a Liquified Natural Gas Storage Facility and is shut to the general public.

33.Dewer's Hollow. (Three Bears Cave, Cardiff, Wales).

Dewer's Hollow is the centre piece of the episode, where the hound is seen by Henry Knight (played by Russell Tovey). It is in fact filmed in Three Bears Cave in Forest Fawr Country Park in Cardiff - which has also been used in Torchwood and Merlin.

34.St. Hilary Church Yard. (Vale of Glamorgan, South Wales).

The church yard scene is a landmark in Sherlock and Watson's relationship as Holmes finally admits that he counts John as his one true friend, after constantly claiming to be friendless. The church yard that was used wasn't in Dartmoor but in South Wales.

35.The Tower Of London. (Cardiff Castle).

BBC

BBC

The Tower Of London takes centre stage in the last episode of series two, with Moriarty carrying out a stunt breaking in and setting up Sherlock for a meeting at the Old Bailey. Internal scenes were actually shot at Cardiff Castle.

36.The Old Bailey.

The Old Bailey sees Moriarty get the attention of the national press as he's put on trial - but he somehow manages to walk out free. Although only the exterior was used. The court appearance took place in the court in Swansea Guildhall, while the police cells were actually in Roath police station.

38.St Aldate's Boarding School. (Tredegar House, Newport, Wales).

Max and Claudine Bruhl were said to be attending the St Aldate's Boarding School before they went missing. The building is actually Tredegar House, a mansion in Newport, Wales - again used several times in Doctor Who.

39.Moriarty's sniper's base. (The American Church in London).

When Moriarty threatens Sherlock at the end of Series 2 he has a sniper placed at a vantage point pointing at Watson. He was actually on the second floor stairwell in the American Church In London in Tottenham Court Road.

40.St Bart's Hospital.

St Bart's Hospital is pivotal throughout the whole of Sherlock. It's where Sherlock and Watson meet for the first time, where Sherlock does a lot of his work with Molly Hooper and appears in each episode. It is perhaps the most memorable location at the end of series two with Sherlock standing on top of the roof after a dramatic run in with Moriarty. All interior scenes were filmed in Cardiff, but St Bart's is based in West Smithfield if you want to see the exterior.

At the start of the third series Watson plans to propose to Mary Morstan while still believing Sherlock is dead. But Sherlock of course interrupts and surprises him after two years of disappearing. In the show we see the outside of The Landmark Hotel in London, but the interior is in fact The Daffodil restaurant in Cheltenham.

Do NOT scroll any further until you have seen the Season 3 finale in the U.S. on Sunday.

44.Sherlock confronts Mary. (Leinster Gardens, London).

In the final episode of season three, His Last Vow, Sherlock realises Mary is not who she says she is and confronts her at Leinster Gardens in London. It has two false facades at numbers 23 and 24, built in the 1860s. In the episode Sherlock beams Mary's face on to the front in her wedding dress before confronting her.

The series ends at Charles Augustus Magnussen's home Appledore, where Sherlock tries to strike up a deal to delete all files on Mary for the sake of Watson. The impressive architectural house is actually called Swinhay House and is in North Nibley.